Known in the art are tools for rolling female threads in which thread rollers are uniformly disposed along the circumference thereof relative to the axis of rotation of the tools and are utilized for rolling threads in plastic, steels and alloys. Such tools can be used for rolling threads of a resilient profile, though in this case only thread-rolling devices having a rigid MDTW gearing (machine-tool-device-tool-workpiece) can be utilized.
Also known in the art is a tool for rolling female threads (USSR Inventor's Certificate No. 108, 253, published Sept. 26, 1956), which tool is a body provided with a tail portion for fixing said body inside a rotating spindle of, for example, a drilling machine. Within the body there are provided thread rollers which are uniformly disposed around the circumference thereof relative to the axis of rotation of said body, the axes of the rollers being in an angular position at an angle equal to the lead angle of the helical line of the thread being rolled.
The profile of the circular grooves of the thread rollers is made in accordance with that of the thread being rolled.
When said body is caused to rotate, the thread rollers also start rotating under the action of friction forces applied against the surface of the thread being rolled, and the body starts screwing into the hole.
Such a tool can be applied in the manufacture of a female thread of a resilient profile inside a through bore, though in this case the provision of a rigid MDTW gearing is required, thus resulting in the complication of the thread-rolling devices. The presence of clearances within the gearing system affects the stability of the resilient properties of the resulting thread.